NEW DELHI -- Seven people were killed and 10 others injured in what could be a tribal conflict when suspected militants from a separatist group in the northeast Indian state of Assam opened fire Sunday night on a group of people in a remote village, said police.

The attackers were believed to be cadres of the Garo National Liberation Army (GNLA) who attacked a village called Gendabari located in Assam's Goalpara district. All the victims were engaged in gambling organiszd on the occasion of Diwali, or festival of lights.

All the injured were rushed to hospital and some of the seriously injured were referred to hospital in the state capital Guwahati, police said.

"We are yet to ascertain the reasons behind the attack. An operation has been launched to nab the militants. The militants were armed with automatic weapons and we suspect the hands of Meghalaya-based GNLA militants behind the incident. However, we could confirm this only after completion of the investigation," a senior police officer told the media.

However, according to local TV channel NCTV, the police said the attack was not a terrorist attack but a local tribal war.

There has been tension brewing among local tribes in the area since last month, particularly due to the proposed election of a local council.